Apparatus for checking the profiles of gear teeth,especially bevel gears



ec. S, 1970 K. H. WEBER 3,546,780 APPARATUS FOR CHECKING THE PROFILES OFGEAR TEETH, ESPECIALLY BEVEL GEARS Filed June 21, 1968 4 Sheets-Sheet lK. H. WEBER Dec., l5, 1970 CHECKENG THE PROFILES OE GEAR TEETH,ESPECIALLY BEVEL GEAEs APPARATUS FOR Filed June 21, 1968 4 Sheets-Sheet2 /nven/ar: Wn/Z Mz?,-

ec. 15, i970 K. H. WEBER 3,546,786

APPARATUS FOR CHECKING THE PROFILES OF GEARy TEETH, ESPECIALLY BEVELGEARS Filed June 2l, 1968 4 Sheets-Sheet 3 l /nve/l lar.' KARL f/E/Nzwggg Dec. l5, 1970 K. H. WEBER CHECKING THE PROFIL ES OF GEAR APPARATUSFOR TEETH, ESPECIALLY BEVEL GEARS 4 Sheets-Shea*l 4 Filed June 21 1968lnvenlor:

United States Patent Int. cl. G6111 /20 U.S. Cl. S23-179.5 3 ClaimsABSTRACT OF THE DISCLOSURE Gear checking apparatus having a base memberin which a rst shaft for supporting a gear is supported on a carriagemounted on the base member for movement transverse to the axis of thefirst shaft with simultaneous rotation of the shaft in the carriage. Thecarriage is adjustable in the direction of the shaft axis and alsoangularly relative to an axis vertical to the axis of the first shaft.

A second carriage on the base member has a second shaft rotatabletherein. The second carriage is adjustable on the base membertransversely to the axis of said second shaft with simultaneous rotationof said second shaft. A feeler adjustably carried by said second shaftengages the gear on said first shaft. A lever interconnects thecarriages for simultaneous transverse movement thereof.

The second shaft is arranged for axial movement in said second carriage.

The present invention relates to an apparatus for checking the profilesof gear teeth, especially bevel gears.

Such apparatus generally includes a support for the gear to be checkedand a support for a feeler and a base common to the supports; thesupports are adjustable angularly about an axis vertical to the base,each support comprising a carriage. A lever pivoted on theaforementioned axis interconnects the carriages for simultaneousmovement. Movements of the carriage pertaining to the gear supportcauses rotation of the gear to be checked that is mounted thereon.Movement of the carriage pertaining to the support Afor the feelercauses rotation of the feeler. The supports are adjustable relatively toaccommodate lfor dif- -ferent types and sizes of gears and the feeler isadjustable on its support during rotation of the gear being checked andthe feeler, the feeler follows the profile of a tooth of the gear. Thepresent invention concerns an improvement in apparatus of theabovementioned type according to which the rolling cylinder associatedwith the feeling device is supported by a stationary shaft. This shaftmay according to a specific embodiment of the said apparatus support afurther rolling transmission lfrom which is derived an additionalmovement. The purpose of this additional movement is a movement of the`feeler in the direction of the height of the teeth.

It is an object of the present invention to provide additional means tobring about the said additional movement according to the presentinvention, the transverse carriage associated with the stationary shaftis connected to adjustable inclined guiding means which impart onto theshaft bearing and thereby also onto the shaft with the feeler deviceconnected thereto an axial movement which is adjustable as to itsmagnitude. A device of this type is characterized by a particularsimplicity.

The invention is illustrated by way of example in the accompanyingdrawings, in which:

FIG. 1 is an isometric view showing an apparatus according to theinvention with a device for axially displacing the feeler head.

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FIG. 2 shows the measuring of the profile with a measuring feelerdisplaceable in axial direction.

FIG. 3 shows an arrangement for a feeler head for producing a movementof the measuring feeler on a ball surface about the tip of the partialcone.

FIG. 4 shows an arrangement for a feeler head, the measuring feeler ofwhich moves on the profile of the normal cut of the replacement tooth.

FIG. 4a is an isometric view of an apparatus as one example in which thefeeler mechanism likewise carries out a turning movement in conformitywith the reference gearing While the feeler head is additionallydisplaced in the direction of the height of the teeth.

Similar to the apparatus disclosed in assignees above identifiedcopending application, the rolling cylinder 6 is supported by a carriage5 which, in its turn, is guided on a rotatable ibase 8, while therolling cylinder 25 associated with the feeler device 17 is mounted on astationary shaft 20. A circular disc 94 provided with inclined guidingmeans 95 is rotatably and arrestably arranged in the broadened tablesurface 93. The inclined guiding means 95 may be adjustable parallel orinclined at will with regard to the direction of movement of thetransverse carriage 27. A stud or pivot 97 inserted in the shaft bearing96 engages the inclined guiding means. If the inclined guiding Imeans isin inclined position and the transverse carriage 27 is displaced, adisplacement of the shaft bearing and of the shaft 20 in the directionof its axis will result. The shaft 20 is coupled to the rolling cylinder25 for rotation therewith by means of a key 20a. In this way it ispossible to impart to the radial adjustable feeler device 17 connectedto shaft 20 the desired additional movement in the direction of theheight of the tooth when the feeler device 20 exerts a rolling movement.

As shown in FIG. 2, the measuring dome or peek 18 of the Ifeeler movesalong a helical line 98 of a cylinder 99 for the radius of which it hasbeen adjusted and which cylinder is circumscribed around the axis 21.This is due to the rotation of the rolling cylinder 25 brought about therolling bands during the displacement of the transverse carriage 27 anddue to the rotation of the shaft 20 and is, furthermore, due to thesimultaneous displacenient in the direction of its axis as caused by thepivot or stud 97. This helical line, when the cylinder is developed intoa plane, corresponds to a straight line and with a corresponding angularadjustment of the inclined guiding means 95 corresponds to the engagingline of the plane appropriate gearing of the bevel gearing (Tredgoldsapproximation). According to the transmission ratio adjusted by theroller Iband' and lever transmission in conformity with the rolling ofthe workpiece on the reference gearing, the measuring dome of the feeleralways contacts the profile or flank of the workpiece at pointspertaining to the common engaging line of the supplementary gearing andrecords the deviation of the shape of the flanks of the workpiece to bechecked Vfrom the rated shape.

With the arrangement according to FIG. 3 which represents an alternativesolution to that of FIG. 2, the measuring dome 18 does not move on thesurface of a cylinder but on a ball surface circumscribed by the commonpartial cone tip of the workpiece to be tested and reference gearing.The feeler device 17 is radially adjustably mounted on an arm of atwo-arm lever 100. This lever is connected to a shaft 101 which isrotatably journalled in a yoke bearing body 102, which, in its turn, isconnected to the rolling cylinder 25. The second yoke-shaped arm oflever 100 extends a bolt 103 which in its turn is connected in an anglepiece screwed fast onto shaft 20.

The operation is as follows: While the work to be tested and the rollingcylinder 25 rotate at their transmission ratio, the shaft 20 rotatingwith the rolling cylinder will Patented Dec. 15, 1970 be axiallydisplaced in conformity with a correspondingly adjusted inclined guidingmeans 95. The rod 103 brings about a rotation of lever 100 with thefeeling device about the shaft 101 which rotates together with therolling cylinder. The measuring dome 18 therefor, moves on the surfaceof the ball 105 for the radius of which it has been adjusted and uponsaid ball 105 moves along a curve which very much resembles the spacialengaging line of the bevel gear ring, inasmuch as rotations by smallangles are involved.

With the spiral cone gears, due to manufacturing conditions, thestraight line flank profile is obtained in normal section of thereference gearing. Therefore, it is expedient to adjust the measuringfeeler for the normal cut of the reference gearing,

FIG. 4 shows an arrangement which permits this adjustment. A supportingframe 106 is connected to the rolling cylinder 25 while the front sideof said frame which faces the workpiece to be checked is provided with aguiding path 107. In this guiding path there is guided a carriage 108which is radially adjustable and arrestable by means of a screw 109. Onthe said carriage 108 there is mounted a cylindrical disc 110 which hasa rectangular window 111, said disc 110 being rotatably adjustable andbeing arrestable by any convenient means not shown. Within said windowthere is pivotally journalled a bearing body 112 which is pivotableabout its axis which is perpendicular to the axis 21. In said bearingbody 112 there is axially adjustable and nonrotatably guided a rod 113which has its front end carrying the feeler device 17 with the measuringdome 18 whereas the other end of said rod 113 carries a roller 114journalled therein. A spring 115y presses the rod 113 against a planeabutment surface 116 at the front end of shaft 20. By rotation of thecylinder disc 110 in conformity with the inclined or spiral angle of therespective tooth and when pivoting the bearing body 117 toward thenormal angle of engagement, the displacement of the rod 113 with themeasuring feeler in the direction of the straight ilank profile asbrought about by the axial movement of the shaft 20 may be adjusted inthe normal cut of the reference gearing. The radius by which themeasurement is to be effected is adjusted by the carriage 108. Thediameter of the engaging surface 116 must be so great that the roller114 will still engage the same by all occurring adjustments.

It is, of course, to be understood that the present invention is notlimited to the specic embodiments referred to above. Thus, for instance,the inclined guiding means for producing the axial supplemental movementmay, contrary to the examples referred to above, act directly upon theshaft rather than upon the shaft bearing.

It is considerably more favorable to employ a pointshaped feeler and tomove the same during the measuring operation additionally in thedirection of the height of the tooth so that in its path it will actlike a measuring edge. Such operation is possible with the designaccording to FIG. 4a.

Fundamentally, the device according to FIG. 4a. corresponds to that ofFIG. 4 in copending U.S. application Ser. No. 738,986, Seybold, iiledconcurrently herewith on June 21, 1968 and belonging to the assignee ofthe present invention. The arrangement of FIG. 4a comprises the shaft 20associated with the feeler mechanism, in addition to the describedroller transmission 23'-25' cooperating with the transverse carriage27', additionally equipped with a further roller transmission, namely,shaft 20', roller bands 38 and carriage 39. Shaft 20 is, by means of aset screw 40' secured against rotation, whereas the roller cylinder isfreely rotatable on the shaft 20'. Fixedly connected to the rollercylinder is an angle member 41' with machined-in guiding groove 42' forthe carriage 39'. This carriage 39 has connected thereto the ends of theroller bands 38. The carriage 39 supports a substantially U-shapedmember 44 which is radially adjustable in the guiding groove 43. Betweenthe legs of U-shaped member 44 there is rotatably journalled a shaft 45.Shaft 45 is adjustable, inclined by the meshing angle 0f the workpieceto be checked with regard to a plane perpendicular to the axis 21. Shaft45 has its central portion provided with a stud or pin 46 which isguided in a groove 47 of a cylindrical disc 48. Connected to disc 48' isa rod 49 with the feeler 50', said rod 49 being guided in the neck of arocker 51 and is secured by a key 52' against rotation. The inclinedposition of groove 47' is adjustable in conformity with the respectiveprevailing conditions. The rocker 51 is journalled in bearings 53 on abase member 54' which is adjustably connected on a guiding body 55 bynonillustrated means. The said guiding body 55' is connected to the legsof the angle member 41'.

The ends of the shaft 45 are journalled in ball cups of sliding shoes56' which are adapted to be displaced in guiding grooves 57 in the legsof the member 44. Shaft 45' consists of three telescopicallyinterengaging members which are pressed apart by springs 58. Whenpivoting the rocker 51' about the axis of the stud 46', the slide shoes56 slide in the guiding grooves 57', and the sections of the shaft 45move into or out of each other. In the adjusted pivoting positions aboutthe axes 0f members 46 and 53, the rocker is adapted to be clamped fastby any convenient means not shown in FIG. 4a.

OPERATION OF THE DEVICE ACCORDING TO FIG. 4a

The operation of the device of FIG. 4a is as follows:

The U-shaped member 44' arranged on the carriage 39 is radially adjustedwith regard to the axis 21 in such a manner that the feeler dome 18rakes the profile of the workpiece to be checked at the predetermineddistance from its pitch cone tip when by turning the hand crank 29 theimaginary reference gearing and the workpiece to be checked roll uponeach other. So far, the movements correspond to those of the deviceaccording to FIG. 1 of the aforementioned copending application.According to FIG. 4a there is an additional movement of the feeler headin the direction of the height of the tooth. If, namely, the anglemember 41 together with the roller cylinder 25 turns about the axis 21and the carriage 39 follows this movement, said carriage 39'simultaneously moves in groove 42 due to the rolling on the stationarilyheld shaft 20 as forced by the roller bands 38. The member 44 is thusmoved along. Shaft 45', stud 46 and inclined guiding means 47 bringabout an axial displacement of the rod 49' and thereby the desiredadditional movement of the feeling device 50J with the feeler dome 18 inthe direction of the height of the tooth.

Due to the tiltability of the rocker 51 about two axes arrangedperpendicularly to each other, the rod 49' can, within certain limits,be adjusted in conformity with any desired direction relative to axis21. In this way it will be possible to move the feeler in conformitywith the rectilinear protile of the tangential sections of the flanks ofthe reference gearing bevel gears with straight or inclined teeth andalso in conformity with the rectilinear prole of the normal section ofthe reference gearing of bevel gears Iwith spiral teeth. inasmuch as themeasuring feeler which moves along a straight path in both instancesrepresents a prole of the reference gearing, the transmission ratio forthe turning movements of the reference gearing and of the workpiece tobe checked, i.e., of the rolling cylinder 25' and the spindle upon whichthe workpiece is tested as shown in the aforementioned copendingapplication is to be adjusted in conformity with the pitch cone angle ofthe workpiece 1' to be checked.

If desired, in view of the adjusting possibilities, the rod 49 carryingthe measuring feeler may also be adjusted in the direction of therectilinear normal profile section of a non-roller spur bevel gear withspiral teeth. In order then to check the flank prole of the teeth of agear associated with said spur bevel gear, it is necessary to adjust thetransmission ratio of the rolling cylinder 25 and the receiving spindleupon which the workpiece is tested as shown in the aforementionedco-pending application in conformity with the teeth ratio of theworkpiece to be checked to the spur bevel gear while the angle of theaxes 3 and 21 must equal the axis angle of the transmission.

What is claimed is:

1. In an apparatus for checking the profiles of gear teeth, especiallybevel gear teeth: a base member, a first support member mounted on saidbase member for pivotal movement thereon about a first axisperpendicular to the base member, a second support member mounted onsaid first support member for movement thereon radial to said firstaxis, a third support member mounted on said second support member formovement thereon transverse to the direction of movement of said secondsupport member, a first shaft rotatable in said second support member,means for rotating said first shaft in response to movement of saidthird support member on said second support member, a fourth supportmember on the opposite side of said first axis from said first supportmember and supported on said base member for movement therein in adirection at right angles to a radius from said first axis, a fifthsupport member adjacent said fourth support member and moveable radiallyof said first axis, a second shaft rotatable but nonaxially moveable insaid fifth support member, a cylindrical portion nonrotatably butaxially moveably carried by said second shaft and rotatably butnonaxially `moveably mounted in said fourth support member, meansresponsive to movement of said fourth support member on said base torotate said cylindrical portion and said second shaft, the line ofintersection of the planes perpendicular to said base member andcontaining the axes of said first and second shafts being coaxial withsaid first axis, a lever pivoted on said first axis and having one armengaging said third support member and another arm engaging said fourthsupport member for simultaneous movement of said third and fourthsupport members, means for mounting a gear on the end of said firstshaft adjacent said first axis, a feeler, means for mounting said feeleron one of said second shaft and cylindrical portion adjacent said firstaxis for engaging the teeth of said gear, and means for adjusting saidfifth support member together With said second shaft means radially ofsaid first amis.

2. An apparatus according to claim 1 which includes a yoke connected tosaid cylindrical portion, a third shaft in the yoke having its axisintersecting the axis of said second shaft, a two arm lever rotatable onsaid third shaft, said feeler being mounted on one arm of said two armlever, the other arm of said two arm lever being fork shaped, a bracketfixed to said second shaft, and a rod fixed to said bracket and engagingsaid fork shaped arm of said two arm lever.

3. An apparatus according to claim 1 which includes an abutment disc onthe end of said second shaft, a bracket connected to said cylindricalportion, a first member slidable on said bracket perpendicular to theaxis of said second shaft, a second member angularly adjustable on saidlirst member, a push rod extending through said first and second membersand having one end engaging said abutment member, spring means urgingsaid push rod toward said abutment member, a pivotal connection betweensaid push rod and said second member, and said feeler being mounted onthe end of said push rod opposite said one end thereof.

References Cited UNITED STATES PATENTS 3,270,425 9/1966 Tishler et al33-179.5(5) 3,321,840 5/1967 Pedersen 33-179.5(5)

SAMUEL S. MATTHEWS, Primary Examiner

